Power-driven fabricating machinery constitutes a primary cause of industrial accidents through crippling or severance of the hands or fingers of the human operators. Barrier type guards have been only partially successful in safeguarding workers, because they can frequently be made inoperative in various rather obvious ways, or cannot be used at all where the work pieces in manufacture require a clear path into and out of the machine operating region. Moreover, work pieces frequently require worker operations thereon while the pieces are set up in working position, under which conditions barriers hinder the operators or sometimes actually contribute a separate hazard to the fabrication operation. Besides, material barriers and their supports are expensive in both first cost and maintenance.
Power cut-offs operational by particular worker body positioning, as by standing on a treadle pad or the like, are not entirely satisfactory, because they are too remote from the worker's hands to provide adequate safeguarding thereof and, besides, can be made inoperative by resting a medium or heavy weight load thereon, thus effectively eliminating the necessary condition of an operator's body location in a restricted safe region.
The objectives of this invention are to provide a relatively inexpensive machine operator safety mechanism, the actuators of which can be worn unobtrusively on the body members most likely to suffer injury without impairing operator mobility and without obstructing free passage of, and working manipulations on, work pieces incident to fabrication, and which cannot be made inoperative by the willful acts of the employees themselves .